Various types of equipment benefit from the inclusion of a deadman switch, which prevents or stops operation if an operator is not present. In some cases, it is desirable that equipment only be operated by an authorized user. Exemplary equipment that benefits from a deadman switch and/or an authorization device includes fueling equipment, such as aviation fueling equipment, as well as a wide variety of other types of equipment. Under typical aviation regulations, a deadman switch should be used when performing any pressure fueling or tender filling operation. Deadman switches are designed to safeguard against circumstances or situations that may delay the suspension of fuel flow. Preferably, a deadman switch should not be jammed or bypassed during any fuel transfer operation. Deadman switch types include the electric deadman switch, pneumatic deadman switch (sometimes called an air deadman switch), and combination air/pneumatic types. The deadman switch is actuated, for example through being in the hands of the operator, during a refueling process.